Telephone subscriber set with a speech current transformer and a polarized alternating current alarm



March 28, 1950 J. PATRY ETAL 2,502,273

TELEPHONE SUBSCRIBER SET WITH A SPEECH CURRENT TRANSFORMER AND APOLARIZED ALTERNATING CURRENT ALARM Filed June 17, 1948 2 Sheets-Sheet 1Fig.3 7 F1 4 INVENTORS Jean Putry 8| Richard Sirub.

March 28, 1950 'J.. PATRY ETAL 2,502,273

TELEPHONE SUBSCRIBER SET WITH A SPEECH CURRENT TRANSFORMER AND APOLARIZED ALTERNATING CURRENT ALARM Filed June 17, 1948 2 Sheets-Sheet 2INVENTORS Jean Pctry &

Richard Srrub.

A TTORNE Patented Mar. 28, 1950 SBEEGH CURRENT TRANSFORMER. ANDAJTPOLARIZ'ED ALTERNATIN G CURRENT [ALARM Jean Patry and "Richard'Striib, '"Zurich, Switzerland, 'assignors to Albiswerk Zurich A. G.,Zurich, Switzerland, a Swiss company Application June 17, 1948,1"SerialN0..33',525 TInISw'itzefland June 14, 1947 "'7 Claims.

' The invention relates to telephone "substation devices '"which combinea spee'ch 'current transformer and'a polarized"alternating-current alarmto 'a' singleunit.

It is "an object of the inventionto'devise such units in such a mannerthat it'is "capable of performing its double .iunctions without eitherfunction impairing the other, i. epsubstahtialhr withoutlossintransforming efficiency and without diminution of'the alarmsensitivity.

"To this end, and .in accordance with the invention, the transformerwindings and the alarm or "ringer'windings are mounted on a commonmagnetizable core with an air gap, and the core ends "adjacentthegapior'm also an equipolar pair'of'pole shoes for one poleof.a,polarizing magnet whose other pole carries an armature movable in'theair gap- "In such a device, the. permanent' flux; and theoperating fluxof theco il windingsoverlap practically in theair. gap only. .Owingtotheseparation of v permanent flux and .operating 'fiux of the excitingcoil, .the .magnetio circuit ofthe coilcan be .designedifor minimumloss; which produces favorable transformingconditions for speech-currentwhen theexcitingcoil is used as a transformer.

These and other objects'and. featureswill be apparent from. the.following .description in conjunction with the embodiments of .the.-.invention exemplified by the drawingsin which gTFi'gfll shows theplanview and.pig...2.-a-.side elevation of a devicein whicha one piece:exciting coil arranged .in the longitudinalzdirection of the air gap;"Fig. 3.shows .a .paniview and Fig. 4a side elevation of another devicein which acne-piece exciting coil is arranged transversally to the airgap; Fig. shows an embodiment with a two-part exciting "coil'in whichthe two coil parts are arranged in symmetrical relationship to the airgap and'the armature is ar-- ranged between the two coilparts; and Fig.'6 shows the=wiring diagram of a 1381615110118 substation equipped witha device according to the invention.

.In Figs. 1 and"2fthe two arm. ends land 3 of the .coil 'core 4 whichare separated fromveach otherlby the air gap I, formanequipolar pairofgpole shoes of the permanent magnet v5. The arm. ends are firmlyscrewed toa piece ofsoft iron 6'which is.fastened to an assembly plate.I-of nonemagnetizable material. The plate -1--also carries the magnetBand two bell domes 8 and 9 arranged excentrically one inside" the other.Attachedto the other pole end "of the permanent magnet-aretwo pieces ofsoft iron I!) s milarito pole shoes .attached by screws t2 which alsoholds. spring member II. A rigid armature I3 iswvelded to'member H atpoint. The-armature is therefore capable of resilient reciprocalmotionwithin-the-"air gap. Whenthe "coil 15, mounted oncored,"is excitedby' alternatingpurrent, the armature I3 is "actuated and transmits itsoscillations'viathe alarm 'clapper'l6"to"the bell domes 8 and"9.

"In'the device of Figs."3 and '4'theairjgap 3|"is formedby'thetwd-arm-ends "Hand 33 of'th'e coilcore "34 which "again? form anequipolar pair of pole shoesof the permanentmagnet 35. This permanentmagnet .and the piece of soft iron '36 are secured to'the assemblyplate.31,"which"also carries the two bell domes 38"and'39. The armature-43 ismade inherently resilient by weakeningit at'the point44 byinotches. its.end remoteiromthe'air'gap'is broadened and rigidly connected to thesecond pole end '4l by Ithe screws "42. The "coil "45" is arrangedtransversally to the'airjgap'and located below thepolarizingmagnetsystem. The .armature, when excited, transmits its oscillations'via'the clapper to the bell domes 38 and 39.

In the device of Fig. 5 two exciting coils 65a and 65b are arranged insymmetrical relationship .to the 'air gap '5! and'have acommon iron core54 whose two arm ends 52and' 53form the air gap. Thepolarizing magnetsystem consists of apermanent'magnet 55, a connecting piece56 betweenthe iron core and the permanent magnet, and an armature 1'63 renderedinherently resilient by'notches (i l. The broadened end 60 of armature63.is rigidly connectedby screws 62 to the "permanent magnet 55 as inthe embodiment accordingto Figs..3.and.4. .The arrangement or thearmature between the .two exciting coilsgives a very compact designtothe coiland permanent magnet system. .A'hemispherical bell dome 58covers this wholesystemand is struck at a' recess 59bythe clapper'fi'fimounted on.the armature 63.

The circuit according 'to Fig. .6 is shownin condition" toreceiveincomingcalls. .Three .coil windings H) I ,i Inland i03=arewoundin the same direction and have .a .common iron .core I04. The'twoarms ends "MI and M2 of this iron. core, which areseparated by the.airgap l40,.orm an equipolar ,pair of pole shoes .ofthe permanentmagnetl43. The resilient armature I44, which is. connected tothe.other.pole..end...ofthe permanent magnet by, apieceoiisof-tiron M5,.is. movable in. the airgap- I40.

In the illustrated condition, the direct-current is .cut off by .a.condenser. 1.05 connected in series to the coil. When alternating -.alarm voltage 1 is received across terminals I09, I ltlyfrom the exchange,.the tarmature is excited and xthe =SU.b-.

scriber is alarmed. When the receiver is picked up, the hook contact l Hcloses and connects the microphone I06 parallel to a circuit consistingof the series connection of winding l! and condenser I05, while the hookcontact H2 connects a circuit consisting of the series connection ofreceiver i0! and condenser Hi8 parallel to winding I02. This establishesthe speech connection. The copper resistance of winding l0! and theresistance of winding I02 may beutilized for side-tone reduction. Themicrophone feed current, which flows through. the windings B02 and 103,premagnetises the coil core 100, so that the armature is not excited bythe speech currents. In the case of automatic dialling, a short-circuitconnection in which the dialling impulse contact I I4 is arranged, isbuilt up in the usual way between the line connections by theshort-circuit contact H3 of the dial.

-The invention is also applicable for local battery systems. It is thenof advantage to use a substation circuit with an auto-transformer. If noauto-transformer is used, it may be necessary to obtain the seriesconnection of the various transformer windings for the speech currentsby means that the polarizing magnet flux due to said mag net and thevariable coreflux due to said winding's are mutually superimposedsubstantially only in said air gap.

5. A telephone substation device, comprising a substantially ring-shapedtransformer core having an air gap and having two end portions facingeachother across said gap, a substation circuit having alarm controlwindings and speechcurrent transformer windings series connected witheach other and disposed on said core away from said'end portions, apermanent magnet having two pole ends, the first of said pole endshaving two mutually spaced pole parts rigidly joined with saidrespective core end portions, the second pole end being magneticallyspaced from said core, and an alarm actuating armature member mounted onsaid second pole end and extending through said gap, said armature beingelastically movabl relative to said core and magnet.

6. A telephone substation device, comprising a generally annulartransformer core having an air gap and having two end portions facingeach other across said gap, a permanent magnet having two pole ends, thefirst of said pole ends having two pole parts joined with said tworespective core end portions, the second pole end being magneticallyspaced from said core, two coil units comprising alarm control windingsand speechcurrent transformer windings and being mounted on said coreaway from said pole parts and symmetrically with respect to said airgap, and an windings on the common iron core, one serving as theexciting coil for the alarm bell while the other represents thetransformer. This results in a substation circuit similar to that usualin conventional telephon set circuits.

We claim as our invention:

1. A telephone substation device, comprising a magnetizable core havingan air gap, a permanent magnet having two pole ends, one of said poleends being joined with a portion of said core which includes said airgap, said one pole H end having two pole parts at the two respectivesides of said air gap, a single coil unit having alarm control windingsand transformer windings and being mounted on said core away from saidcor portion, and an armature member mounted on said other pole end andmovable in said air gap.

2. In a telephone substation device according to claim 1, said core andsaid magnet extending in substantially parallel planes respectively, and

said coil unit having an axis substantially parallel to the longitudinaldirection of said armature.

3. In a telephone substation device according to claim 1, said core andsaid magnet extending in respective planes substantially perpendicularto each other, and said coil unit having an axis transverse to thelongitudinal direction of said armature.

4. A telephone substation device, comprising a transformer core havingtwo pole faces facing each other and having an air gap between saidfaces, alarm control windings disposed on said core, speech-currenttransformer windings also disposed on said core, a polarizing magnethaving two poles, the first of said magnet poles being joined with saidcore and being divided into two portions bordering said respective polefaces, and an armature member mounted on the second pole and movablyextending through said air gap, so

armature member mounted on said other pole end and movable in said airgap.

7. A telephone substation device, comprising a generally annulartransformer core having an air gap and having two end portions facingeach other across said gap, a permanent magnet having two pole ends, thefirst of said pole ends having two pole parts joined with said tworespective .core end portions, the second pole end being magneticallyspaced from said core, a substation circuit, two coil units comprisingalarm control windings and speech-current transformer windings connectedin said circuit in series relation to each other, said two coil unitsbeing mounted on said core away from said core portion and.

symmetrical with respect to said air gap, and an armature memberdisposed between said two coil units, said armature member being mountedon said second pole end and extending movably through said air gap.

JEAN PATRY. RICHARD STRUB.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number

